ScienceDaily (Nov. 5, 2010) — Evolutionary divergence of humans and chimpanzees likely occurred some 8 million years ago rather than the 5 million year estimate widely accepted by scientists, a new statistical model suggests.

The revised estimate of when the human species parted ways from its closest primate relatives should enable scientists to better interpret the history of human evolution, said Robert D. Martin, curator of biological anthropology at the Field Museum, and a co-author of the new study appearing in the journal Systematic Biology.

Working with mathematicians, anthropologists and molecular biologists, Martin has long sought to integrate evolutionary information derived from genetic material in various species with the fossil record to get a more complete picture.

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I am posting this as an example of how science works, and how it improves it's models (theories) step by step as new data are discovered and as new approaches are explored.

Also, this illustrates the changes in our understanding of human evolution that are coming from the biological sciences. We no longer have to rely just on paleontology and fossils.

But most importantly, we see that two independent lines of investigation are pointing in the same direction: what paleontology has shown us dimly, biological studies are showing us much more clearly. And it is likely that this trend will continue, and accelerate, in the future.

I have no idea where this should be placed.

Edited by Admin, : Change title.

Religious belief does not constitute scientific evidence, nor does it convey scientific knowledge.

I'm going to put this in Is It Science?, because in conjunction with past changes in this estimate it does raise questions about whether we're really improving our knowledge or are just continually changing our minds in line with the latest evidence. For instance, this is from Study moves chimp-human split to 4 million years ago in Reuters three years ago:

Reuters writes:

Chimpanzees and humans split from a common ancestor just 4 million years ago -- a much shorter time than current estimates of 5 million to 7 million years ago, according to a study published on Friday.

First the split was 5-7 million years ago (and who knows what it was before that), then it was 4 million years ago, then it was 5 million years ago, now it's 8 million years ago. Aren't these guys just making it up as they go along?

First the split was 5-7 million years ago (and who knows what it was before that), then it was 4 million years ago, then it was 5 million years ago, now it's 8 million years ago. Aren't these guys just making it up as they go along?

That's one of the problems with science journalism. Science is a process -- and a messy one at that. But journalists need to report events. So they report on each new study as if the investigators had found the Holy Grail.

In time, a consensus will probably emerge. More fossils will be found. Statistical models will be improved or abandoned. Molecular clocks will be better calibrated. Personally, I'd trust the fossils over the statistical models and molecular clocks.

In the meantime, 4-8 million years ago is not such an imprecise estimate when measured on a geologic timescale.

I'm baffled by the claim that 5 million years is "widely accepted by scientists". Even the recent dates suggested by DNA are 5-6 million years, and it's widely accepted that they're an underestimate especially as we have fossils dated to 6-7 million years that are thought to be in the clade containing us but not the clade containing chimps.

And, well, new statistical model. Hmm... not exactly cast iron evidence is it? We'll see whether the techniques used stand the test of time.